Well, I may not be gay, but the thought of 3-5 days a month where my girlfriend/wife/etc basically goes batshit has always scared me. 2 younger sisters both over the age of 21 now, I got to experience periods first hand....man I wish I could have seen those coming and gotten out of dodge. No super power can save you from a hormonal lady who ran out of midol.

...that's where I'd draw the line. If she needs me to swim in the red river to help ease her cramps a little, I'd probably do it on the condition that I get to sport warpaint like a warrior about to plunge into the thick of battle. Drinking from it... no thank you.

In college, I saw one of my friends after he'd drank from the red river and he looked like something out of a horror movie; his beard was all gory looking. It took me years to unsee that.

EDIT: But lemme tell you, tampons can be a punk or metal musician's best friend (along with duct tape.) Why you ask? Moshpits. This one dude told me a story where this guy took a massive elbow to the face and this girl shoved two of her tampons up his nostrils.

I had this discussion before with coworkers years ago. My power would be the ability to regulate the temperature immediately around me and experience a comfortable 75 degrees Fahrenheit with a slight breeze and sunshine. I could walk outside in a pair of shorts and a t-shirt no matter where I'd go, whether it be rain, snow, or swimming in a pool of lava. I'd always feel great.

Don't forget about adding the stipulations of not having it trigger during a smug fueled monologue about making somebody do something horrible and batshit insane against their will, and not having a rear end in a top hat running around undoing your handiwork and landing you in a whole heap of trouble.